In a radio communication system, a base station communicates with an equipment via an uplink/downlink, wherein the downlink (forward direction) is a direction from the base station to the terminal, and uplink (reverse direction) is a direction from the terminal to the base station. In general application, a plurality of terminals can send data to the base station via the uplinks simultaneously, and also can receive data from the base station via the downlinks simultaneously.
In a radio communication system based on Orthogonal Frequency Division Multiple Access (“OFDMA” for short) technology, a base station maps and allocates radio resources, while users realize multiple access by occupying different subcarriers. For instance, a base station provides system configuration and resource allocation information in downlink transmission from the base station to terminals, and system configuration and resource allocation information in uplink transmission from the terminals to the base station, etc. The system configuration and resource allocation information usually are sent by a control channel, and the terminals receive the information via a determined control channel for sending and receiving data and communication with the base station.
In the radio communication system, system information is sent mainly via Synchronization Channel (“SCH” for short) and Broadcast Control Channel (“BCCH” for short). The synchronization channel and the broadcast control channel are “point-to-multipoint” one-way control channels. The synchronization channel serves the main function of providing to the terminal the temporal correction and the frequency during the initial access and simultaneously carrying a small amount of system information. The broadcast control channel serves the main function of allowing the base station broadcasting to the terminal necessary system configuration and control information that indicates the control structure of the whole system, and especially    indicates mapping and configuring condition of the system resources. As a result, only when the terminal correctly decodes the synchronization channel and the broadcast control channel and obtains necessary system configuration and control information, it can access the base station, and further performs data transmission. However, the terminal does not obtain the resource mapping information before decoding the broadcast control channel, and in order to assure a synchronous signal to be capable of serving an auxiliary function for decoding the broadcast control channel, the resource structure of the synchronization channel should be taken into consideration in mapping resources of the broadcast control channel.
Therefore, an effective method for mapping the resources of the broadcast control channel is needed.